Flame resistant fabric with tracing yarns

ABSTRACT

A flame resistant fabric with tracing yarns includes a flame resistant fabric with a first non-tracing yarn, and a second tracing yarn. The first non-tracing yarn and/or the second tracing yarn include flame resistant fibers being selected from the group consisting of inherently flame resistant fibers and treated fibers. When the flame resistant fabric is exposed to heat, flames, long-term excessive UV light, or the like, the first non-tracing yarn is adapted to hold its color and the second tracing yarn is adapted to change colors.

RELATED APPLICATION

This application claims the benefit of co-pending provisionalapplication Ser. No. 61/429,915 filed Jan. 5, 2011.

FIELD OF THE INVENTION

The instant invention is directed toward a flame resistant fabric,namely, a flame resistant fabric with tracing yarns for notifying a userwhen a garment and its components needs to be examined and/or replaceddue to high heat exposure, flame exposure, long-term overexposure toultraviolet (UV) light, or the like.

BACKGROUND OF THE INVENTION

Flame resistant fabrics are those fabrics made from flame resistantfibers, also known as FR fibers, and blends of flame resistant fibers.Some flame resistant fabrics may also include a minority of non-FRfibers that are blended with flame resistant fibers. Flame resistantfibers, or FR fibers, are those fibers that have flame resistance as anessential characteristic of the fiber. Flame resistant fibers could beinherently flame resistant fibers or fibers treated to become flameresistant. Typically, a treated fiber is a conventional textile fiberthat has been treated with a flame retardant, or a chemical substanceused to impart flame resistance. Not only can the fiber be treated witha flame retardant, but the resulting fabric can also be treated with aflame retardant to make the fabric flame resistant. For example, treatedfibers or fabrics include: FR cotton, FR-treated rayon (both FRcellulosics), and the like. Inherently flame resistant fibers mayinclude: aramids, polyamide imides, melamines, polybenzimidazole (PBI),polyimides, polyphenylene benzodisoxazole (PBO), polyphenylene sulfide(PPS), carbon, Polytetrafluoroethylene (PTFE), polyetherether ketone(PEEK), modacrylic, inherently-FR rayon, liquid crystal polymers, andthe like.

Most often these flame resistant fibers (treated and/or inherent) areblended together to obtain a yarn for a fabric with a particular blendof preferred properties. The preferred properties include thermalprotection, static resistance, comfort, durability, stability,appearance, moisture management, abrasion resistance, anti-bacterial,ease of laundry maintenance, color, relative cost, etc., andcombinations thereof. As a result, flame resistant fabrics can be usedfor many different purposes and in many different industries. Theseinclude, but are not limited to, the fire service industry, military,law enforcement, wildland fires, urban search and rescue incidents, infoundries, at electrical utilities, in the chemical, oil, gas, andpetrochemical industries, in auto racing, areas of rioting, and illicitdrug manufacturing labs, just to mention a few. One specific example ofa use for a flame resistant fabric is the outer shell fabric of afirefighter's personal protective garment used in structural fires, alsoknown as the outer shell fabric for fireman's turnout gear.

With such a broad range of application, it should be understood thatthere exists a need for flame resistant fabrics in many different colorsand shades of colors. Typically, flame resistant fibers and fabrics areprovided in various colors and shades by dyeing the fabric or yarn, alsoknown as piece-dyeing or yarn-dyeing. For example, a process ofpiece-dyeing or yarn-dyeing a PBI fiber to a black color is to add a dyeto the fabric after it is produced or to add a dye to the yarn after itis produced. One problem with traditional piece-dyed or yarn-dyed flameresistant fabrics is sublimation of the dyes from the fabric due to highheat exposure, flame exposure, and fading due to long-term excessive UVexposure, or the like. For example, a traditionally yarn-dyed blackPBI/para-aramid flame resistant fabric when exposed to significant heatmay cause the fabric to change to a reddish brown color in the area ofheat exposure. As another example, a traditionally piece-dyed blackPBI/para-aramid flame resistant fabric when exposed to significant heatexposure can cause the fabric to change to a similar reddish brown colorin the area of the heat exposure. This overall color change of thefabric is clearly not desirable.

Another way to produce a colored flame resistant fabric is to utilizesolution-dyed fibers. Solution-dyeing, also known as dope-dyeing orproducer-dyeing, is a process where a colorant is added to the chemicalcompound before extrusion of the fiber. There are numerous known meansof producing solution-dyed fibers. It has been found that flameresistant fabrics constructed of solution-dyed flame resistant fibersretain their color far better than piece-dyed or yarn-dyed fabrics aftersignificant heat exposure, flame exposure, long-term overexposure to UVlight, etc., or any other factors which may fade color of piece-dyed oryarn-dyed fabrics. Keeping with the previous examples, a blackPBI/para-aramid fabric that is solution dyed has held far more of itsblack color than the yarn-dyed or piece-dyed PBI/para-aramid fabricexamples discussed above and does not turn to the reddish brown colorwhen exposed to high heat. This minimal color change is clearly anadvantage over the piece-dyed and yarn-dyed fabrics. However, because ofthe minimal color change, one of the problems discovered with solutiondyed flame resistant fabrics is that they do not indicate when thefabric has been exposed to any significant heat exposure, flameexposure, long-term overexposure to UV light, etc., as with thepiece-dyed and yarn-dyed fabrics. As a result, the solution dyed flameresistant fabrics do not indicate when the garment and its componentsneed to be evaluated for further damages.

The instant invention is designed to solve the problem with bothpiece-dyed/yarn-dyed flame resistant fabrics and solution dyed flameresistant fabrics by providing a way to keep the positive attribute of afabric made of solution-dyed fibers, (minimal overall color change,i.e., maximum colorfastness) while still providing some sort ofindicator to the end-user that the garment had seen a high heatexposure, flame exposure, excessive UV light exposure, or other factorswhich may fade color of piece-dyed and yarn-dyed fibers.

The instant invention of a flame resistant fabric with tracing yarns isdesigned to address the above mentioned problems.

SUMMARY OF THE INVENTION

The instant invention is directed toward a flame resistant fabric withtracing yarns. The flame resistant fabric with tracing yarns includes aflame resistant fabric with a first non-tracing yarn, and a secondtracing yarn. The first non-tracing yarn and/or the second tracing yarninclude flame resistant fibers being selected from the group consistingof inherently flame resistant fibers and treated fibers. When the flameresistant fabric is exposed to heat, flames, long-term excessive UVlight, or the like, the first non-tracing yarn is adapted to hold itscolor and the second tracing yarn is adapted to change colors.

BRIEF DESCRIPTION OF THE DRAWINGS

For the purpose of illustrating the invention, there is shown in thedrawings a form that is presently preferred; it being understood,however, that this invention is not limited to the precise arrangementsand instrumentalities shown.

FIG. 1A is one embodiment of a flame resistant fabric with tracing yarnsinserted at regular intervals in both the warp and the weft directions.

FIG. 1B is the flame resistant fabric with tracing yarns shown in FIG.1A where the tracing yarns inserted at regular intervals in both thewarp and the weft directions have changed colors after being exposed tohigh heat, flames, long-term excessive UV light, or the like.

FIG. 2A is one embodiment of a flame resistant fabric with tracing yarnsinserted at random intervals in the warp direction of the fabric.

FIG. 2B is the flame resistant fabric with tracing yarns shown in FIG.2A where the tracing yarns inserted at random intervals in the warpdirection have changed colors after being exposed to high heat, flames,long-term excessive UV light, or the like.

FIG. 3A is one embodiment of a flame resistant fabric with tracing yarnsinserted at random intervals in the weft direction of the fabric.

FIG. 3B is the flame resistant fabric with tracing yarns shown in FIG.3A where the tracing yarns inserted at random intervals in the weftdirection have changed colors after being exposed to high heat, flames,long-term excessive UV light, or the like.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the drawings, wherein like numerals indicate like elements,there is shown in FIGS. 1-3 an embodiment of a flame resistant fabric 10with tracing yarns. Flame resistant fabric 10 with tracing yarns may befor providing a flame resistant fabric that has minimal dye sublimationwhen exposed to high heat and/or flames, or fading due to long-termexcessive UV light exposure, or the like. In other words, flameresistant fabric 10 may have good overall color fastness when exposed tohigh heat, flames, long-term excessive UV light, or the like. However,flame resistant fabric 10 may also provide an indication to the wearerthat the fabric has been exposed to high heat, flames, excessive UVlight, or the like by the color change of the tracing yarns inserted inthe fabric. As a result, the flame resistant fabric 10 with tracingyarns of the instant invention is designed to solve the problem withboth piece-dyed/yarn-dyed flame resistant fabrics and solution dyedflame resistant fabrics by providing a way to keep the positiveattribute of a fabric made of solution-dyed fibers, (minimal overallcolor change, i.e., maximum colorfastness) while still providing somesort of indicator to the end-user that the garment had seen a high heatexposure, flame exposure, long-term excessive UV light exposure, orother factors which may fade color of piece-dyed and yarn-dyed fibers.

Flame resistant fabric 10 with tracing yarns may generally include aflame resistant fabric including: a first non-tracing yarn 12 and asecond tracing yarn 14. When the flame resistant fabric 10 may beexposed to heat 16 (as depicted in the Figures), flames, long-termexcessive UV light, or other factors which may fade color, the firstnon-tracing yarn 12 may be adapted to hold its overall color, while thesecond tracing yarn 14 may be adapted to change colors. As a result, theinstant invention provides a flame resistant fabric that holds itsoverall color when exposed to heat, excessive UV light, or other factorswhich may fade the color of the fibers, while providing a visibleindication of heat, excessive UV light, etc. exposure on a portion ofthe fabric.

First non-tracing yarns 12 may be included in flame resistant fabric 10with tracing yarns of the instant invention. See FIGS. 1-3. Firstnon-tracing yarns 12 are any yarns that do not significantly changecolors or have less color change than piece-dyed or yarn-dyed fiberswhen exposed to heat, long-term excessive UV light, etc., or otherfactors which may fade the color of the piece-dyed or yarn-dyed fibersin flame resistant fabrics. For example, first non-tracing yarns 12 mayinclude, but are not limited to, solution-dyed fibers. In oneembodiment, the first non-tracing yarn 12 of the instant invention maybe made of entirely solution-dyed flame resistant fibers. In otherembodiments, first non-tracing yarn 12 may be made of other types ofdyed fibers that have good color fastness. The first non-tracing yarn 12may be present in any amount in the flame resistant fabric. In oneembodiment, the first non-tracing yarn 12 may be greater than 50% of theyarns in the flame resistant fabric 10. In another embodiment, the firstnon-tracing yarn 12 may be greater than 75% of the yarns in the flameresistant fabric 10. In yet another embodiment, the first non-tracingyarns 12 may be greater than 90% of the yarns in the flame resistantfabric 10.

Second tracing yarns 14 may be included in the flame resistant fabric 10with tracing yarns of the instant invention. See FIGS. 1-3. Secondtracing yarns 14 may be any yarns that change color when exposed toheat, excessive UV light, or other factors which may fade the color offlame resistant fabrics. For example, second tracing yarns 14 mayinclude, but are not limited to, yarn-dyed yarns, or piece-dyed yarns.In one embodiment, the second tracing yarn 14 of the instant inventionmay be a yarn-dyed yarn. The second non-tracing yarn 14 may be presentin any amount in the flame resistant fabric. The amount of secondtracing yarns 14 present in flame resistant fabric 10 may be based onthe desired amount of color change in the fabric or the desired patternutilized to indicate the exposure to heat, flames, excessive UV light,etc. In one embodiment, the second tracing yarn 14 may be less than 50%of the yarns in flame resistant fabric 10. In another embodiment, thesecond tracing yarn 14 may be less than 25% of the yarns in the flameresistant fabric 10. In yet another embodiment, the second tracing yarn14 may be less than 10% of the yarns in the flame resistant fabric 10.

The flame resistant fabric 10 with tracing yarns of the instantinvention may be any type of fabric, including, but not limited to, awoven fabric, a non-woven fabric, or a knitted fabric. The secondtracing yarns 14 may be randomly inserted in the flame resistant fabric,or they may be inserted at regular intervals in the flame resistantfabric. In some embodiments, the second tracing yarn may be insertedrandomly in the warp and/or weft direction of the flame resistantfabric. In other embodiments, the second tracing yarn may be inserted inthe warp and/or weft directions of the flame resistant fabric at regularintervals.

Referring to the first Figure, in FIG. 1A an embodiment of a flameresistant fabric with tracing yarns inserted at regular intervals inboth the warp and the weft directions is shown. As shown in FIG. 1B,once the fabric is exposed to the heat or flames 16 (could also belong-term excessive UV light exposure of the like), the tracing yarnsinserted at regular intervals in both the warp and the weft directionshave changed colors after being exposed to the heat of flames 16. Thischange in color creates a grid or boxed pattern in flame resistantfabric 10, which will indicate to the user that the garment and itscomponents needs to be examined and/or replaced.

Referring to the second Figure, in FIG. 2A an embodiment of a flameresistant fabric with tracing yarns inserted at random intervals in thewarp direction is shown. As shown in FIG. 2B, once the fabric is exposedto heat or flames 16 (could also be long-term excessive UV lightexposure or the like), the tracing yarns inserted at random intervals inthe warp direction have changed colors after being exposed to the heatof flames 16. This change in color creates a vertical line pattern inflame resistant fabric 10, which will indicate to the user that thegarment and its components needs to be examined and/or replaced.

Referring to the third Figure, in FIG. 3A an embodiment of a flameresistant fabric with tracing yarns inserted at random intervals in theweft direction is shown. As shown in FIG. 3B, once the fabric is exposedto heat or flames 16 (could also be long-term excessive UV lightexposure or the like), the tracing yarns inserted at random intervals inthe weft direction have changed colors after being exposed to the heatof flames 16. This change in color creates a horizontal line pattern inflame resistant fabric 10, which will indicate to the user that thegarment and its components needs to be examined and/or replaced.

The first non-tracing yarns 12 and/or the second tracing yarns 14 of theflame resistant fabric 10 with tracing yarns of the instant inventionmay include flame resistant fibers. The flame resistant fibers may beany flame resistant fibers, including, but not limited to, inherentlyflame resistant fibers and treated flame resistant fibers. Theinherently flame resistant fibers may be, but are not limited to,aramids, polyamide imides, melamines, polybenzimidazole (PBI),polyimides, polyphenylene benzodisoxazole (PBO), polyphenylene sulfide(PPS), Polytetrafluoroethylene (PTFE), polyetherether ketone (PEEK),modacrylic, inherently-FR rayon, liquid crystal polymers, the like, andcombinations thereof. The treated flame resistant fibers may be, but arenot limited to, FR cotton, FR-treated rayon, the like, and combinationsthereof. In one embodiment, the flame resistant fibers may be PBI.

The first non-tracing yarns 12 and/or the second tracing yarns 14 of theflame resistant fabric 10 with tracing yarns of the instant inventionmay further comprise non-FR fibers. The non-FR fibers may be any non-FRfibers, including, but not limited to, cotton, rayon, polyester, or thelike. The non-FR fibers may be included within the first yarn 12 and/orthe second yarn 14, or the non-FR fibers may be spun into a third yarnthat is included in the flame resistant fabric 10.

The instant invention also includes a method of manufacturing flameresistant fabric 10 with tracing yarns. This method may include anysteps for creating flame resistant fabric 10 with tracing yarns. In oneembodiment, this method may include, but is not limited to, thefollowing steps: a step of providing a plurality of first non-tracingyarns 12; a step of providing a plurality of second tracing yarns 14;and a step of creating a flame resistant fabric 10 including the firstnon-tracing yarns 12 and the second tracing yarns 14. Whereby, when theflame resistant fabric 10 created by this method is exposed to heat,flames, excessive UV light, or the like, the first non-tracing yarns 12may be adapted to hold their color and the second tracing yarns 14 maybe adapted to change colors. In one embodiment, the step of creating aflame resistant fabric may include a step of inserting the secondtracing yarn randomly or at regular intervals in the warp directionand/or weft direction of flame resistant fabric 10. This method ofmanufacturing flame resistant fabric 10 may also include any other stepsfor creating flame resistant fabric 10 with tracing yarns, as describedabove.

EXAMPLES

An example flame resistant fabric with tracing yarns was createdaccording to the instant invention. The fabric was a black woven fabricthat included tracing yarns and non-tracing yarns. The Tracing yarnswere a blend of 60% p-aramid and 40% PBI. The yarns were constructed ofnatural PBI and p-aramid, and were subsequently package dyed to producethe black yarn. The non-tracing yarns were also a blend of 60% p-aramidand 40% PBI. The non-tracing yarns were constructed using solution-dyedBlack PBI and solution-dyed Black p-aramid. The tracing yarns wereinserted in the weft direction at regular intervals and made up between4-5% by weight of the resulting fabric.

A swatch of the example flame resistant fabric with tracing yarns wasfirst tested with a 10-second Thermal Protection Performance (TPP)exposure. The TPP exposure was 2 cal/cm2-s heat flux (about 1800F),combination flame and radiant heat. This TPP exposure caused the tracingyarns to change colors while the non-tracing yarns had very goodcolorfastness. The results of the TPP exposure created reddish brownstripes that clearly showed up in the black fabric.

A second swatch of the example flame resistant fabric with tracing yarnswas then tested with a 10-second Radiant Protective Performance (RPP)exposure. The RPP exposure was 1 cal/cm2-s heat flux, radiant heat only.Similar to the TPP exposure, the RPP exposure caused the tracing yarnsto change colors while the non-tracing yarns had very goodcolorfastness. The results of the RPP test created reddish brown stripesthat clearly showed up in the black flame resistant fabric.

A third swatch of the example flame resistant fabric with tracing yarnswas then tested to ensure that both the non-tracing and tracing yarnshad good color fastness after being washed. The fabric was washed 5times as required by NFPA 1971, Standard on Protective Ensembles forStructural Fire Fighting and Proximity Fire Fighting (2007 Edition). Theresults of these tests showed that there was no indication of colorchange/stripes after laundry, i.e. both the tracing yarns andnon-tracing yarns maintained their black color.

The present invention may be embodied in other forms without departingfrom the spirit and the essential attributes thereof, and, accordingly,reference should be made to the appended claims, rather than to theforegoing specification, as indicated in the scope of the invention.

1. A flame resistant fabric with tracing yarns comprising: a flameresistant fabric including: a first non-tracing yarn; and a secondtracing yarn; wherein said first non-tracing yarn and/or said secondtracing yarn comprising flame resistant fibers being selected from thegroup consisting of inherently flame resistant fibers and treatedfibers; whereby, when said flame resistant fabric being exposed to heat,flames, excessive UV light, or the like, said first non-tracing yarnbeing adapted to hold its color and said second tracing yarn beingadapted to change colors.
 2. The flame resistant fabric with tracingyarns of claim 1 wherein said non-tracing fibers being solution dyedfibers and said tracing yarn being yarn-dyed.
 3. The flame resistantfabric with tracing yarns of claim 1 wherein said fabric being selectedfrom the group consisting of: a woven fabric, a non-woven fabric, and aknitted fabric.
 4. The flame resistant fabric with tracing yarns ofclaim 1 wherein: said first non-tracing yarn being greater than 50% ofsaid yarns in said flame resistant fabric; and said second tracing yarnbeing less than 50% of said yarns in said flame resistant fabric.
 5. Theflame resistant fabric with tracing yarns of claim 4 wherein: said firstnon-tracing yarn being greater than 75% of said yarns in said flameresistant fabric; and said second tracing yarn being less than 25% ofsaid yarns in said flame resistant fabric.
 6. The flame resistant fabricwith tracing yarns of claim 4 wherein: said first non-tracing yarn beinggreater than 90% of said yarns in said flame resistant fabric; and saidsecond tracing yarn being less than 10% of said yarns in said flameresistant fabric.
 7. The flame resistant fabric with tracing yarns ofclaim 1 wherein said second tracing yarn being randomly inserted in thewarp direction and/or weft direction of said flame resistant fabric. 8.The flame resistant fabric with tracing yarns of claim 1 wherein saidsecond tracing yarn being inserted at regular intervals in the warpdirection and/or weft direction of said flame resistant fabric atregular intervals.
 9. The flame resistant fabric with tracing yarns ofclaim 1 wherein: said inherently flame resistant fibers being selectedfrom the group consisting of: aramids, polyamide imides, melamines,polybenzimidazole (PBI), polyimides, polyphenylene benzodisoxazole(PBO), polyphenylene sulfide (PPS), carbon, Polytetrafluoroethylene(PTFE), polyetherether ketone (PEEK), modacrylic, inherently-FR Rayon,liquid crystal polymers, and combinations thereof; and said treatedflame resistant fibers being selected from the group consisting of: FRcotton, FR-treated rayon, and combinations thereof.
 10. The flameresistant fabric with tracing yarns of claim 9 wherein said inherentlyflame resistant fiber comprising polybenzimidazole (PBI).
 11. The flameresistant fabric with tracing yarns of claim 1 herein said first and/orsaid second yarns further comprising non-FR fibers.
 12. A flameresistant fabric with tracing yarns comprising: a flame resistant fabricbeing selected from the group consisting of: a woven fabric, a non-wovenfabric, and a knitted fabric; said flame resistant fabric including: afirst non-tracing yarn being solution dyed fibers; and a second tracingyarn being yarn-dyed; said first non-tracing yarn being greater than 75%of said yarns in said flame resistant fabric; and said second tracingyarn being less than 25% of said yarns in said flame resistant fabric;wherein said first non-tracing yarn and/or said second tracing yarncomprising flame resistant fibers being selected from the groupconsisting of inherently flame resistant fibers and treated fibers;whereby, when said flame resistant fabric being exposed to heat, flames,long-term excessive UV light, or the like, said first non-tracing yarnbeing adapted to hold its color and said second tracing yarn beingadapted to change colors.
 13. The flame resistant fabric with tracingyarns of claim 12 wherein: said first non-tracing yarn being greaterthan 90% of said yarns in said flame resistant fabric; and said secondtracing yarn being less than 10% of said yarns in said flame resistantfabric.
 14. The flame resistant fabric with tracing yarns of claim 12wherein said second tracing yarn being randomly inserted in the warpdirection and/or weft direction of said flame resistant fabric.
 15. Theflame resistant fabric with tracing yarns of claim 12 wherein saidsecond tracing yarn being inserted at regular intervals in the warpdirection and/or weft direction of said flame resistant fabric atregular intervals.
 16. The flame resistant fabric with tracing yarns ofclaim 12 wherein: said inherently flame resistant fibers being selectedfrom the group consisting of: aramids, polyamide imides, melamines,polybenzimidazole (PBI), polyimides, polyphenylene benzodisoxazole(PBO), polyphenylene sulfide (PPS), carbon, Polytetrafluoroethylene(PTFE), polyetherether ketone (PEEK), modacrylic, inherently-FR Rayon,liquid crystal polymers, and combinations thereof; and said treatedflame resistant fibers being selected from the group consisting of: FRcotton, FR-treated rayon, and combinations thereof.
 17. The flameresistant fabric with tracing yarns of claim 16 wherein said inherentlyflame resistant fiber comprising polybenzimidazole (PBI).
 18. The flameresistant fabric with tracing yarns of claim 20 wherein said firstand/or said second yarns further comprising non-FR fibers.
 19. A methodof manufacturing a flame resistant fabric with tracing yarns comprisingthe step of: providing a plurality of first non-tracing yarns; providinga plurality of second tracing yarns; and creating a flame resistantfabric including said first non-tracing yarns and said second tracingyarns. whereby; when said flame resistant fabric being exposed to heat,flames, long-term excessive UV light, or the like, said firstnon-tracing yarn being adapted to hold its color and said second tracingyarn being adapted to change colors.
 20. The method of manufacturing aflame resistant fabric with tracing yarns of claim 19 wherein: said stepof creating a flame resistant fabric including inserting said secondtracing yarn randomly or at regular intervals in the warp directionand/or weft direction of said flame resistant fabric.